U.S. OFFICIALS SAY SUMMIT LIKELY IN '85

The White House, encouraged by a positive signal from Moscow, now views a summit between President Reagan and Soviet leader Mikhail Gorbachev as likely this year, administration officials said Tuesday.

They said Gorbachev, in a message sent through diplomatic channels, tentatively accepted the summit invitation Reagan sent to Moscow last month with Vice President George Bush.

Despite the nod of approval from Moscow, however, the officials emphasized there has been no agreement on a specific time or place for such a meeting, which would be the first full-scale U.S.-Soviet summit in more than five years.

These details, as well as the rough agenda for the meeting, will be the focus of further discussion and could surface in talks May 15 in Vienna between Secretary of State George Shultz and Soviet Foreign Minister Andrei Gromyko.

In the meantime, the officials said, the White House is awaiting a more detailed response from Gorbachev.

"What we have is acceptance of an idea," one official said. "There is a considerable amount of work that must be done before it becomes a reality."

Guarding against what one aide dubbed "summit fever," Reagan confirmed that Gorbachev had responded to his summit invitation and, in an interview with The Washington Post, said he was "hopeful that we can have such a meeting."

Later he told reporters: "It's always encouraging to get a letter in response to your own." When asked whether the ball was in the U.S. or Soviet court, Reagan shot back, "Theirs."

However, another administration official said the ball "is somewhere in the middle," with the prospects for a summit later this year dependent on how soon either of the superpowers comes forward with specific proposals agreeable to the other.

Bush conveyed the summit invitation to Gorbachev while in Moscow to attend the funeral of Soviet leader Konstantin Chernenko. U.S. officials said the Soviet response was delivered last week through routine diplomatic channels.

"I wrote and he answered and we're in negotiations," Reagan said. "And we'll just leave it at that."

White House spokesman Larry Speakes said the "negotiations" mentioned by Reagan were the arms talks in Geneva.

The last full-scale summit between an American president and his Soviet counterpart was in June 1979, when Jimmy Carter and Leonid Brezhnev met in Vienna to sign the SALT II agreement.